A number of commercial reference works with expired copyrights have recently found their way online. These works include: Roget's Thesaurus, Webster's Dictionary, Bartlett's Dictionary of Quotations, and Strunk and White's Manual of Style. The free online versions all have expired copyrights; Roget's (1911), Webster's (unknown), Strunk and White's (1918), and Bartlett's (1901). "[The] number of years used in calculating [copyright] durations has changed, from either 28 or 56 to either 50, 75 or 100, depending on the type of work." [copyright FAQ] Recently, I have begun to see these online versions heavily referenced. All of these works are still in production today in a current and updated print form. The publishers have not been slow to make the current forms available online, for a fee. Most major reference works are now available on CD-ROM and increasingly via subscription online. Some examples are: Encyclopedia Brittanica Online which also contains Merriam-Webster's Collegiate Dictionary, and the Oxford English Dictionary - a commonly exported CD-ROM. Additionally, most major commercial services such as Compuserve, America Online, and Prodigy have their own licensed reference selections.
This raises some interesting questions in terms of access and equity. Will free access to current reference works, such as in public libraries, end when libraries become digital libraries? Access to commercial quality reference works is expanded to anyone with access to the net as there are no restrictions on works with expired copyrights. However, it seems quite possible that these works will gain wide acceptance and possibly become "standard and or authoritative" beyond their years due to the fact that they are free and easily available on the net.
This said, I would be very interested in a discussion of access and equality in terms of online works especially references and other academic works. For example, what effects might this have on various academic disciplines, or even science in general. How prevalent is using a free work over a paid one, even if the free one is out of date to some degree? If you have any comments or would like to continue this discussion, send me email or stop by SigCAS or SigIR.
Bibliography:
ARTFL Project: ROGET Form http://humanities.uchicago.edu/forms_unrest/ROGET.html
Bartlett, John. 1901. Familiar Quotations http://www.columbia.edu/acis/bartleby/bartlett/
Hypertext Webster Interface http://c.gp.cs.cmu.edu:5103/prog/webster
Strunk, William. 1918. The Elements of Style http://www.columbia.edu/acis/bartleby/strunk/
Copyright Frequently Asked Questions ftp://uiarchive.cso.uiuc.edu/pub/doc/rtfm/usenet-by-group/news.answers/law/copyright/faq/